Organic light emitting diode display device

ABSTRACT

An organic light emitting diode display device includes a substrate, a plurality of organic light emitting diodes on the substrate, a thin film encapsulation layer on the organic light emitting diodes, and at least one sensor on the thin film encapsulation layer, the sensor including a sensing gate electrode, an oxide semiconductor layer overlapping the sensing gate electrode, a sensing source electrode connected to the oxide semiconductor layer, and a sensing drain electrode spaced apart from the sensing source electrode and connected to the oxide semiconductor layer.

CROSS-REFERENCE TO RELATED APPLICATIONS

This is a continuation application based on pending application Ser. No.15/693,908, filed Sep. 1, 2017, the entire contents of which is herebyincorporated by reference.

Korean Patent Application No. 10-2016-0115055, filed on Sep. 7, 2016, inthe Korean Intellectual Property Office, and entitled: “Organic LightEmitting Diode Display Device,” is incorporated by reference herein inits entirety.

BACKGROUND 1. Field

Embodiments relate to an organic light emitting diode (“OLED”) displaydevice.

2. Description of the Related Art

An organic light emitting diode (“OLED”) display device is aself-luminous display device that displays an image using an OLEDemitting light. An OLED display device does not require a separate lightsource and thus may have a relatively small thickness and weight.Further, OLED display devices are garnering attention as next generationdisplay devices for portable electronic devices because they have highquality characteristics such as low power consumption, high luminance,and high reaction speed.

The above information disclosed in this Background section is only forenhancement of understanding of the background of the inventive concept,and, therefore, it may contain information that does not form the priorart that is already known in this country to a person of ordinary skillin the art.

SUMMARY

Embodiments are directed to an organic light emitting diode displaydevice, including a substrate, a plurality of organic light emittingdiodes on the substrate, a thin film encapsulation layer on the organiclight emitting diodes, and at least one sensor on the thin filmencapsulation layer, the sensor including a sensing gate electrode, anoxide semiconductor layer overlapping the sensing gate electrode, asensing source electrode connected to the oxide semiconductor layer, anda sensing drain electrode spaced apart from the sensing source electrodeand connected to the oxide semiconductor layer.

The sensor may be between adjacent organic light emitting diodes.

The organic light emitting diode may include a first electrode, anorganic light emitting layer on the first electrode, and a secondelectrode on the organic light emitting layer. The sensing gateelectrode may be spaced apart from the first electrode in a lateraldirection.

The organic light emitting diode display device may further include apixel defining layer between the first electrodes, the sensor verticallyoverlapping the pixel defining layer.

The oxide semiconductor layer may include at least one of: zinc oxide(ZnO), zinc-tin oxide (ZTO), zinc-indium oxide (ZIO), indium oxide(InO), titanium oxide (TiO), indium-gallium-zinc oxide (IGZO), andindium-zinc-tin oxide (IZTO).

The oxide semiconductor layer may have photoreactivity.

The oxide semiconductor layer may absorb a visible light.

The visible light may change an electric charge mobility of the oxidesemiconductor layer.

The oxide semiconductor layer may have an electric charge mobilityvarying according to a wavelength of the visible light.

The oxide semiconductor layer may have thermal sensitivity.

The oxide semiconductor layer may absorb infrared light, and theinfrared light may change an electric charge mobility of the oxidesemiconductor layer.

The organic light emitting diode may be connected to a thin filmtransistor, the thin film transistor may be connected to a gate line onthe substrate and a data line on the substrate, the data lineintersecting the gate line, the sensing gate electrode may be connectedto a reset line parallel to one of the gate line and the data line, andthe sensing source electrode may be connected to a sensor power lineparallel to another of the gate line and the data line.

The sensing drain electrode may be connected to an output line parallelto one of the gate line and the data line.

The organic light emitting diode display device may further include alight blocking layer between the thin film encapsulation layer and thesensor.

The organic light emitting diode display device may further include acolor filter on the sensor.

The sensor may be a fingerprint recognition sensor.

The thin film encapsulation layer may include a laminate of inorganicand organic layers, the inorganic and organic layers being interposedbetween the oxide semiconductor layer and an upper electrode of theorganic light emitting diode.

Embodiments are also directed to an organic light emitting diode device,including a substrate, a plurality of organic light emitting diodes onthe substrate, a thin film encapsulation layer on the organic lightemitting diodes, and a fingerprint recognition sensor on the thin filmencapsulation layer, the fingerprint recognition sensor including atleast one sensor that includes a sensing gate electrode, an oxidesemiconductor layer overlapping the sensing gate electrode, a sensingsource electrode connected to the oxide semiconductor layer, and asensing drain electrode spaced apart from the sensing source electrodeand connected to the oxide semiconductor layer.

The organic light emitting diode display device may further include afingerprint recognition storage storing a fingerprint information of auser.

The fingerprint recognition sensor may be on the thin film encapsulationlayer.

The organic light emitting diode display device may further include apixel defining layer between the organic light emitting diodes, thesensor vertically overlapping the pixel defining layer.

BRIEF DESCRIPTION OF THE DRAWINGS

Features will become apparent to those of skill in the art by describingin detail example embodiments with reference to the attached drawings inwhich:

FIG. 1 illustrates a plan view of an organic light emitting diode(“OLED”) display device according to a first example embodiment;

FIG. 2 illustrates a circuit diagram of a pixel and a sensor illustratedin FIG. 1;

FIG. 3 illustrates a plan view of the pixel and the sensor illustratedin FIG. 1;

FIG. 4 illustrates a cross-sectional view taken along line II-II′ ofFIG. 3;

FIG. 5 illustrates a cross-sectional view taken along line I-I′ of FIG.1;

FIG. 6 illustrates a cross-sectional view illustrating a touch input;

FIG. 7 illustrates a plan view of a pixel of an OLED display deviceaccording to a second example embodiment;

FIG. 8 illustrates a circuit diagram of one pixel in FIG. 7;

FIG. 9 illustrates a cross-sectional view of an OLED display deviceaccording to a third example embodiment;

FIG. 10 illustrates a cross-sectional view of an OLED display deviceaccording to a fourth example embodiment; and

FIG. 11 illustrates a plan view of an OLED display device according to afifth example embodiment.

DETAILED DESCRIPTION

Example embodiments will now be described more fully hereinafter withreference to the accompanying drawings; however, they may be embodied indifferent forms and should not be construed as limited to theembodiments set forth herein. Rather, these embodiments are provided sothat this disclosure will be thorough and complete, and will fullyconvey example implementations to those skilled in the art. In thedrawing figures, the dimensions of layers and regions may be exaggeratedfor clarity of illustration. Like reference numerals refer to likeelements throughout.

When a layer, area, or plate is referred to as being “on” another layer,area, or plate, it may be directly on the other layer, area, or plate,or intervening layers, areas, or plates may be present therebetween.Conversely, when a layer, area, or plate is referred to as being“directly on” another layer, area, or plate, intervening layers, areas,or plates may be absent therebetween. Further when a layer, area, orplate is referred to as being “below” another layer, area, or plate, itmay be directly below the other layer, area, or plate, or interveninglayers, areas, or plates may be present therebetween. Conversely, when alayer, area, or plate is referred to as being “directly below” anotherlayer, area, or plate, intervening layers, areas, or plates may beabsent therebetween.

The spatially relative terms “below”, “beneath”, “less”, “above”,“upper”, and the like, may be used herein for ease of description todescribe the relations between one element or component and anotherelement or component as illustrated in the drawings. It will beunderstood that the spatially relative terms are intended to encompassdifferent orientations of the device in use or operation, in addition tothe orientation depicted in the drawings. For example, in the case wherea device shown in the drawing is turned over, the device positioned“below” or “beneath” another device may be placed “above” anotherdevice. Accordingly, the illustrative term “below” may include both thelower and upper positions. The device may also be oriented in the otherdirection, and thus the spatially relative terms may be interpreteddifferently depending on the orientations.

Throughout the specification, when an element is referred to as being“connected” to another element, the element is “directly connected” tothe other element, or “electrically connected” to the other element withone or more intervening elements interposed therebetween. It will befurther understood that the terms “comprises,” “comprising,” “includes”and/or “including,” when used in this specification, specify thepresence of stated features, integers, steps, operations, elements,and/or components, but do not preclude the presence or addition of oneor more other features, integers, steps, operations, elements,components, and/or groups thereof.

It will be understood that, although the terms “first,” “second,”“third,” and the like may be used herein to describe various elements,these elements should not be limited by these terms. These terms areonly used to distinguish one element from another element. Thus, “afirst element” discussed below could be termed “a second element” or “athird element,” and “a second element” and “a third element” can betermed likewise without departing from the teachings herein.

Unless otherwise defined, all terms used herein (including technical andscientific terms) have the same meaning as commonly understood by thoseskilled in the art to which this invention pertains. It will be furtherunderstood that terms, such as those defined in commonly useddictionaries, should be interpreted as having a meaning that isconsistent with their meaning in the context of the relevant art andwill not be interpreted in an ideal or excessively formal sense unlessclearly defined in the present specification.

Hereinafter, a first example embodiment will be described with referenceto FIGS. 1, 2, 3, and 4.

As illustrated in FIG. 1, an organic light emitting diode (“OLED”)display device 101 according to the first example embodiment includes apixel PX and a sensor SP at a display area DA. Each of a plurality ofthe pixels PX includes an OLED 310. Sensors SP may be disposed among theplurality of pixels PX on a plane. The sensors SP may be arranged in aselective manner. For example, the sensors SP may be disposed only at apart of the display area DA.

The OLED display device 101 may include light emission drivers 911 and912 connected to the pixels PX to drive the pixels PX, and includessensor drivers 921 and 922 connected to the sensors SP to drive thesensors SP. The light emission drivers may include a first lightemission driver 911 applying data signals to the pixels PX, and mayinclude a second light emission driver 912 applying gate signals to thepixels PX. The sensor drivers may include a first sensor driver 921receiving detection signals from the sensors SP, and may include asecond sensor driver 922 applying reset signals to the sensors SP. Thesecond light emission driver 912 and the second sensor driver 922 may bedisposed, for example, at a non-display area NDA of a substrate 211, asshown in to FIG. 1.

In addition, the OLED display device 101 may include a light emissioncontrol 910 configured to control the light emission drivers 911 and912, a sensing control 920 configured to control the sensor drivers 921and 922, and a main control 900 connected to the sensing control 920.

The light emission control 910 may control the first light emissiondriver 911 and the second light emission driver 912. The light emissioncontrol 910 may include an image processing circuit or the likeconfigured to process an image.

The sensing control 920 may control the first sensor driver 921 and thesecond sensor driver 922, and may interpret the detection signaltransmitted from the first sensor driver 921.

The main control 900 may include a central processing (CPU) configuredto perform various kinds of arithmetic processing, an arithmetic circuitfor image processing, a memory circuit, and the like.

In other implementations, the configurations and roles of each of thedrivers 911, 912, 921, and 922 and the controls 910, 920, and 900 may bevariously modified.

The sensor SP according to the first example embodiment may sense lightand may operate as a touch sensor. For example, a difference in currentaccording to a difference in an amount of light an oxide semiconductorlayer has received may be detected so that whether or not a touch actionis performed on a corresponding area may be identified.

An information input process and an information output process of theOLED display device 101 will be described below.

The sensor SP may convert light incident thereto into an electric signaland transmit the electric signal to the first sensor driver 921. Thesensing control 920 may interpret the detection signal transmitted tothe first sensor driver 921 to determine a selected position. The maincontrol 900 may transmit a signal to the light emission control 910based on an information, interpreted by the sensing control 920, forexample, an information that a predetermined icon on the screen has beenselected. The emission control 910 may transmit the signal to the lightemission drivers 911 and 912, and the light emission drivers 911 and 912may transmit an image signal to each pixel PX, which emit lightaccording to the image signal applied thereto, thus displaying an image.

In the present example embodiment, referring to FIG. 2, the pixel PX mayinclude an OLED 310 and a plurality of light emission thin filmtransistors (“TFTs”) 10 and 20, and the sensor SP may include a sensingTFT 30.

The OLED display device 101 may include a gate line 251, a data line271, a light emission power line 272, a sensor power line 438, a resetline 436, an output line 437, and the like.

Hereinafter, the pixel PX and the sensor SP will be described in detailwith reference to FIGS. 2 and 3.

According to the first example embodiment, the pixel PX has a 2Tr-1Capstructure including the OLED 310, a switching TFT 10, a driving TFT 20,and a capacitor 80. In other implementations, the pixel PX may includethree or more light emission TFTs and two or more light emissioncapacitors.

The light emission TFTs and the light emission capacitor may constitutea compensation circuit. The compensation circuit may improve uniformityof pixels PX in respective pixel areas, which may substantially suppressdeviations in image quality. In general, the compensation circuit mayinclude two to eight TFTs.

In FIG. 2, the sensor SP includes one sensing TFT 30 but the sensor SPmay include, for example, two or more sensing TFTs, and may furtherinclude a photosensor.

The sensing TFT 30 may include a sensing gate electrode 431, an oxidesemiconductor layer 420, a sensing source electrode 432, and a sensingdrain electrode 433, and the oxide semiconductor layer 420 may havephotoelectric conversion characteristics.

In the present example embodiment, the sensing gate electrode 431 of thesensing TFT 30 is connected to the reset line 436, the sensing sourceelectrode 432 is connected to the sensor power line 438, and the sensingdrain electrode 433 is connected to the output line 437.

In an example embodiment, by a signal of the reset line 436, the sensingTFT 30 connected to the reset line 436 is selected to be turned on. Insuch an example embodiment, upon irradiation of light to the oxidesemiconductor layer 420, a current may vary. For example, a currentflowing through the oxide semiconductor layer 420 varies between caseswhere light is irradiated and where light is not irradiated. Based onthe difference in current, whether or not the oxide semiconductor layer420 is irradiated with light may be identified. In addition, an amountof current variation may be proportional to an intensity of lightirradiated to the oxide semiconductor layer 420. Accordingly, theintensity of light may be identified based on the amount of currentvariation. For example, when a user touches a screen, an intensity of alight the oxide semiconductor layer 420 receives may vary. Accordingly,a difference in current according to a difference in an amount of lightthe oxide semiconductor layer 420 has received may be detected so thatwhether or not a touch action is performed on a corresponding area maybe identified.

The configurations of the pixel PX and the sensor SP may be variouslymodified.

With the above-described configuration, the OLED display device 101 maysimultaneously display and input information, using the pixel PX and thesensor SP. In addition, according to the first example embodiment, onesensing TFT 30 may constitute one sensor SP. Accordingly, the OLEDdisplay device 101 according to the first example embodiment may achieveimproved performance while having a relatively simple structure.

Hereinafter, the OLED display device 101 will be described in detailwith reference to FIGS. 3 and 4, focusing on a stacked structure.

FIG. 3 is a plan view illustrating the OLED display device 101 accordingto the first example embodiment, and FIG. 4 is a cross-sectional viewtaken along line II-II′ of FIG. 3.

The OLED display device 101 according to the first example embodimentmay include the substrate 211, a pixel circuit 230, and the OLED 310.

The substrate 211 may include, for example, an insulating materialselected from the group of glass, quartz, ceramic, plastic, and thelike. In addition, the substrate 211 may include a polymer film.

A buffer layer 220 may be disposed on the substrate 211. The bufferlayer 220 may include, for example, one or more layers selected fromvarious inorganic layers and organic layers.

The pixel circuit 230 may be disposed on the buffer layer 220. The pixelcircuit 230 may include a plurality of TFTs 10 and 20 and drive the OLED310. For example, the OLED 310 may emit light according to a drivingsignal applied from the pixel circuit 230 to display an image.

FIGS. 3 and 4 illustrate an active matrix-type organic light emittingdiode (AMOLED) display device 101 having a 2Tr-1Cap structure. Forexample, the 2Tr-1Cap structure may include two TFTs, e.g., a switchingTFT 10 and a driving TFT 20, and one capacitor 80 in each pixel, but theOLED display device 101 may include, for example, three or more TFTs andtwo or more capacitors in each pixel, and may further include additionalwirings. Herein, the term “pixel” refers to a smallest element fordisplaying an image, and the OLED display device 101 displays an imageusing a plurality of pixels.

Each pixel may include the switching TFT 10, the driving TFT 20, thecapacitor 80, and the OLED 310. The gate line 251 extending along onedirection, and the data line 271 and the light emission power line 272insulated from and intersecting the gate line 251 may be disposed at thepixel circuit 230. Each pixel may be defined by the gate line 251, thedata line 271, and the light emission power line 272 as a boundary, butthe pixels may be defined by, for example, a pixel defining layer 290 ora black matrix.

The OLED 310 may include a first electrode 311, an organic lightemitting layer 312 on the first electrode 311, and a second electrode313 on the organic light emitting layer 312. The organic light emittinglayer 312 may include a low molecular weight organic material or a highmolecular weight organic material. Holes and electrons may be appliedfrom the first electrode 311 and the second electrode 313, respectively,into the organic light emitting layer 312 and then combined with eachother therein to form an exciton. The OLED 310 may emit light by energygenerated when the exciton falls from an excited state to a groundstate.

The capacitor 80 may include a pair of capacitor plates 258 and 278, andan insulating interlayer 260 interposed therebetween. In such an exampleembodiment, the insulating interlayer 260 may be a dielectric element. Acapacitance of the capacitor 80 is determined by electric chargesaccumulated in the capacitor 80 and a voltage across the pair ofcapacitor plates 258 and 278.

The switching TFT 10 may include a switching semiconductor layer 231, aswitching gate electrode 252, a switching source electrode 273, and aswitching drain electrode 274. The driving TFT 20 may include a drivingsemiconductor layer 232, a driving gate electrode 255, a driving sourceelectrode 276, and a driving drain electrode 277. A gate insulatinglayer 240 may be further provided to insulate the semiconductor layers231 and 232 and the gate electrodes 252 and 255.

The switching TFT 10 may function as a switching element which selects apixel to perform light emission. In the present example embodiment, theswitching gate electrode 252 is connected to the gate line 251, and theswitching source electrode 273 is connected to the data line 271. Theswitching drain electrode 274 is spaced apart from the switching sourceelectrode 273 and connected to one of the capacitor plates, e.g., thecapacitor plate 258.

In the present example embodiment, the driving TFT 20 applies a drivingpower, which allows the organic light emitting layer 312 of the OLED 310in a selected pixel to emit light, to the first electrode 311 which is apixel electrode. The driving gate electrode 255 is connected to thecapacitor plate 258 that is connected to the switching drain electrode274. Each of the driving source electrode 276 and the other of thecapacitor plates, e.g., the capacitor plate 278, is connected to thelight emission power line 272. The driving drain electrode 277 isconnected to the first electrode 311 of the OLED 310 through a contacthole defined in a planarization layer 265.

With the above-described structure, the switching TFT 10 is operatedbased on a gate voltage applied to the gate line 251 and serves totransmit a data voltage applied to the data line 271 to the driving TFT20. A voltage equivalent to a difference between a common voltageapplied to the driving TFT 20 from the light emission power line 272 andthe data voltage transmitted by (or from) the switching TFT 10 is storedin the capacitor 80, and a current corresponding to the voltage storedin the capacitor 80 flows to the OLED 310 through the driving TFT 20such that the OLED 310 may emit light.

According to the first example embodiment, the first electrode 311 is ananode.

The first electrode 311 may be a transmissive electrode having lighttransmittance or a reflective electrode having light reflectivity. Thesecond electrode 313 may include a semi-transmissive layer or areflective layer.

According to the first example embodiment, the first electrode 311 is areflective electrode, and the second electrode 313 is asemi-transmissive electrode. A light generated in the organic lightemitting layer 312 may pass through the second electrode 313 to beemitted outwards.

One or more a hole injection layer HIL or a hole transporting layer HTLmay be disposed between the first electrode 311 and the organic lightemitting layer 312, and one or more of an electron transporting layerETL or an electron injection layer EIL may be disposed between theorganic light emitting layer 312 and the second electrode 313. Theorganic light emitting layer 312, the hole injection layer HIL, the holetransporting layer HTL, the electron transporting layer ETL, and theelectron injection layer EIL may each include an organic material, andthus may be referred to as an organic layer.

In the present example embodiment, the pixel defining layer 290 has anaperture. The aperture of the pixel defining layer 290 exposes a portionof the first electrode 311. The organic light emitting layer 312 and thesecond electrode 313 are sequentially stacked on the first electrode 311at the aperture of the pixel defining layer 290. In such an exampleembodiment, the second electrode 213 may also be disposed on the pixeldefining layer 290 as well as on the organic light emitting layer 312.In addition, the HIL, the HTL, the ETL, and the EIL may also be disposedbetween the pixel defining layer 290 and the second electrode 313. TheOLED 310 emits light from the organic light emitting layer 312 in theaperture of the pixel defining layer 290. As such, the pixel defininglayer 290 may define a light emission area.

A capping layer may be disposed on the second electrode 313 to protectthe OLED 310 from the external environment.

According to the first example embodiment, a thin film encapsulationlayer 350 is disposed on the OLED 310. In more detail, the thin filmencapsulation layer 350 is disposed on the second electrode 313. Thethin film encapsulation layer 350 may include at least one inorganiclayer 351 and 353 and at least one organic layer 352 to prevent externalair, such as moisture or oxygen, from permeating into the OLED 310. Thethin film encapsulation layer 350 may have a structure in which at leastone inorganic layer 351 and 353 and at least one organic layer 352 arealternately stacked. In FIG. 1, the thin film encapsulation layer 350includes two inorganic layers 351 and 353 and one organic layer 352, butother numbers of layers may be used.

Each of the inorganic layers 351 and 353 may include one or moreinorganic materials selected from the group of: Al₂O₃, TiO₂, ZrO, SiO₂,AlON, AlN, SiON, Si₃N₄, ZnO, and Ta₂O₅. The inorganic layers 351 and 353may be formed through methods such as, for example, a chemical vapordeposition (CVD) method or an atomic layer deposition (ALD) method.

The organic layer 352 may include a polymer-based material. Examples ofthe polymer-based material may include, for example, an acrylic resin,an epoxy resin, polyimide, and polyethylene. In addition, the organiclayer 352 may be formed through a thermal deposition process. Thethermal deposition process for forming the organic layer 352 may beperformed at a temperature range that may not damage the OLED 310.

The inorganic layers 351 and 353 which have a high density of thin filmmay prevent or efficiently reduce infiltration of, mostly, moisture oroxygen. Infiltration of moisture and oxygen into the OLED 310 may belargely prevented by the inorganic layers 351 and 353. Moisture andoxygen that have passed through the inorganic layers 351 and 353 mayfurther be blocked by the organic layer 352. The organic layer 352 mayhave relatively low moisture-infiltration preventing effect, as comparedto the inorganic layers 351 and 353. However, the organic layer 352 mayalso serve as a buffer layer to reduce stress among respective ones ofthe inorganic layers 351 and 353 and the organic layer 352, in additionto the moisture-infiltration preventing function. Further, since theorganic layer 352 has planarization characteristics, an uppermostsurface of the thin film encapsulation layer 350 may be planarized bythe organic layer 352.

The thin film encapsulation layer 350 may have a thickness of, forexample, about 10 μm or less. Accordingly, the OLED display device 101may also have a significantly small thickness. By applying the thin filmencapsulation layer 350 in such a manner, the OLED display device 101may have flexible characteristics.

The sensing TFT 30 may be disposed on the thin film encapsulation layer350. One sensing TFT 30 may constitute one sensor SP.

Referring to FIGS. 3 and 4, the reset line 436 and the sensing gateelectrode 431 protruding from the reset line 436 are disposed on thethin film encapsulation layer 350. The reset line 436 may be disposedparallel to one of the gate line 251 and the data line 271 connected tothe TFTs 10 and 20 of the OLED 310. Referring to FIG. 3, the reset line436 is parallel to the gate line 251 of the OLED 310.

In the present example embodiment, the sensing gate electrode 431 doesnot overlap the first electrode 311 in order not to interfere withemission of light generated in the OLED 310. For example, the sensinggate electrode 431 is spaced apart from the first electrode 311 on aplane.

In the present example embodiment, the sensor SP is disposed among theOLEDs 310 on a plane. Referring to FIGS. 3 and 4, the pixel defininglayer 290 is disposed between the first electrodes 311, and the sensorSP is disposed on the pixel defining layer 290.

According to the first example embodiment, the sensing gate electrode431 is disposed on the pixel defining layer 290. Accordingly, the sensorSP is formed on the pixel defining layer 290 such that an aperture ratioof the OLED display device 101 is not reduced.

A first insulating layer 451 is disposed on the reset line 436 and thesensing gate electrode 431. The first insulating layer 451 has lighttransmittance and may be disposed over an entire surface of the thinfilm encapsulation layer 350.

The oxide semiconductor layer 420 is disposed on the first insulatinglayer 451. The oxide semiconductor layer 420 includes an oxidesemiconductor. Examples of the oxide semiconductor may include, forexample, oxides based on zinc (Zn), indium (In), gallium (Ga), tin (Sn),titanium (Ti), and alloys thereof. The oxide semiconductor layer 420 mayinclude at least one of zinc oxide (ZnO), zinc-tin oxide (ZTO),zinc-indium oxide (ZIO), indium oxide (InO), titanium oxide (TiO),indium-gallium-zinc oxide (IGZO), and indium-zinc-tin oxide (IZTO).

Further, the sensor power line 438 and the output line 437 are disposedon the first insulating layer 451. The sensor power line 438 may bedisposed parallel to one of the gate line 251 and the data line 271connected to the TFTs 10 and 20 of the OLED 310. Referring to FIG. 3,the sensor power line 438 is parallel to the light emission power line272 and the output line 437 is parallel to the data line 271.

The sensor power line 438 and the output line 437 do not overlap thefirst electrode 311 in order not to interfere with emission of lightgenerated in the OLED 310. For example, the sensor power line 438 andthe output line 437 are spaced apart from the first electrode 311 on aplane.

The sensing source electrode 432 extending from the sensor power line438 partially overlaps the oxide semiconductor layer 420 and the sensingdrain electrode 433 extending from the output line 437 partiallyoverlaps the oxide semiconductor layer 420. The sensing source electrode432 and the sensing drain electrode 433 are spaced apart from eachother, and a portion of the oxide semiconductor layer 420 is exposedbetween the sensing source electrode 432 and the sensing drain electrode433. An external stimulus such as light is transmitted to the sensor SPthrough the exposed portion of the oxide semiconductor layer 420.

In addition, a second insulating layer 452 is disposed over an entiresurface of the thin film encapsulation layer 350 including the sensingsource electrode 432, the sensing drain electrode 433, and the exposedportion of the oxide semiconductor layer 420. The second insulatinglayer 452 has light transmittance.

The oxide semiconductor layer 420 may have photoreactivity. For example,the oxide semiconductor layer 420 may absorb visible light. The visiblelight may change electric charge mobility of the oxide semiconductorlayer 420. In such an example embodiment, whether or not the sensing TFT30 is irradiated with light may be identified by measuring a change incurrent flowing through the sensing TFT 30.

In an implementation, the oxide semiconductor layer 420 may have anelectric charge mobility that varies depending on the wavelength ofvisible light.

The oxide semiconductor layer 420 may have thermal sensitivity. Forexample, the oxide semiconductor layer 420 may absorb infrared light,and the infrared light may change the electric charge mobility of theoxide semiconductor layer 420.

According to the first example embodiment, one sensing TFT 30 mayconstitute one sensor SP. Thus, the OLED display device 101 may have arelatively simple structure.

FIG. 5 is a cross-sectional view taken along line I-I′ of FIG. 1.

In detail, FIG. 5 illustrates an edge of the substrate 211. Referring toFIG. 5, the second electrode 313 of the OLED 310 extends to thenon-display area NDA of the substrate 211 to be connected to a commonvoltage wiring 315. Accordingly, a common voltage is applied to thesecond electrode 313.

In the present example embodiment, the thin film encapsulation layer 350extends to the non-display area NDA to cover the second electrode 313and the common voltage wiring 315. The organic layer 352 of the thinfilm encapsulation layer 350 does not extend to an end of the substrate211 and the two inorganic layers 351 and 353 contact each other at anedge of the substrate 211. The two inorganic layers 351 and 353 contacteach other, thus forming an end of the thin film encapsulation layer350.

The output line 437 connected to the sensing drain electrode 433 isdisposed on the inorganic layer 353 of the thin film encapsulation layer350 and extends to the non-display area NDA of the substrate 211. Theoutput line 437 is connected to an output pad 439. The output pad 439 isdisposed at an end portion of the thin film encapsulation layer 350formed by the two inorganic layers 351 and 353 in contact with eachother. The output line 437 and the output pad 439 may be manufacturedthrough substantially a same process using substantially a samematerial.

The output line 437 is connected to the first sensor driving 921 throughthe output pad 439. The first sensor driving 921 is not directly formedon the substrate 211 but may be provided in the form of a flexibleprinted circuit board (“FPCB”) to be connected to the output pad 439extending from the output line 437. In another implementation, the firstsensor driving 921 may be formed directly on the substrate 211.

FIG. 6 is a cross-sectional view illustrating a touch input.

The sensing TFT 30 according to the first example embodiment may serveas a touch sensor.

In the example embodiment shown in FIG. 6, the second insulating layer452 is disposed on the sensor SP including the sensing TFT 30, a bufferlayer 511 is disposed on the second insulating layer 452, and a window511 is disposed on the buffer layer 511. The buffer layer 511 mayinclude an adhesive. The buffer layer 511 including the adhesive maybond the window 510 and the second insulating layer 452.

As illustrated in FIG. 6, the OLED display device 101 may include thewindow 510. In such an example embodiment, a light generated in the OLED310 is emitted through the window 510. Accordingly, a surface of thewindow 510 becomes a display surface.

In the case where a finger FG of a user contacts the window 510 or movesnear the window 510, lights L1 and L2 emitted in the OLED 310 arereflected from the finger FG to reach the oxide semiconductor layer 420of the sensing TFT 30.

Accordingly, a current flowing through the sensing TFT 30 changes, andbased on this, the sensing control 920 and the main control 900 maydetermine that there is a touch input near the corresponding sensing TFT30.

In more detail, after the sensing TFT 30 connected to the reset line 436is selected and turned on by the signal of the reset line 436, in thecase where the lights L1 or L2 are irradiated to the oxide semiconductorlayer 420, the current may vary. Based on this difference in current, itmay be identified that there is a touch input near the sensing TFT 30including the oxide semiconductor layer 420.

FIG. 7 is a plan view illustrating a pixel of an OLED display device 102according to a second example embodiment, and FIG. 8 is a circuitdiagram illustrating one pixel in FIG. 7.

FIG. 7 illustrates four pixels and two sensing TFTs 30 disposed amongthe four pixels. Each pixel illustrated in FIGS. 7 and 8 includes adriving TFT T1, a switching TFT T2, one or more capacitors Ca and Cb, ascan line SCAN[n], a data line DATA[m], a first power line ELVDD, asecond power line ELVSS, and an OLED.

In addition, additional TFTs T3, T4, T5, and T6 including an additionalscan line SCAN[n−1], a light emission control line EM[n], aninitialization voltage wiring Vint, and a compensation TFT T3 mayfurther be provided in the pixel. An initialization voltage transmittedthrough the initialization voltage wiring Vint may serve to initializethe driving TFT.

The switching TFT T2 performs a switching operation according to a scansignal transmitted through the scan line SCAN[n]. For example, a gateelectrode of the switching TFT T2 is connected to the scan line SCAN[n].A source electrode of the switching TFT T2 is connected to the data lineDATA[m]. The scan line SCAN[n] and the data line DATA[m] are formed indirections intersecting each other. A drain electrode of the switchingTFT T2 is electrically connected to a source electrode of the drivingTFT T1 and the first power line ELVDD.

The driving TFT T1 receives a data signal based on a switching operationof the switching TFT T2 and applies a driving current to the OLED.

A gate electrode of the driving TFT T1 is connected to one electrode ofa first capacitor Ca. Another electrode of the first capacitor Ca isconnected to the first power line ELVDD.

The first power line ELVDD is arranged parallel to the data lineDATA[m]. A drain electrode of the driving TFT T1 is electricallyconnected to an anode of the OLED. A cathode of the OLED is connected tothe second power line ELVSS. Accordingly, the OLED receives the drivingcurrent from the driving TFT T1 to emit light.

The OLED includes the anode injecting holes, the cathode injectingelectrons, and a light emitting layer between the anode and the cathode.

Referring to FIG. 7, the sensing TFT 30 includes a sensing gateelectrode 431, an oxide semiconductor layer 420, a sensing sourceelectrode 432, and a sensing drain electrode 433. In an exampleembodiment, the oxide semiconductor layer 420 may have photoelectricconversion characteristics. The sensing gate electrode 431 of thesensing TFT 30 is connected to a reset line 436, the sensing sourceelectrode 432 is connected to a sensor power line 438, and the sensingdrain electrode 433 is connected to an output line 437.

The reset line 436 may be disposed parallel to one of the initializationvoltage wiring Vint, the scan line SCAN[n], the additional scan lineSCAN[n−1], and the light emission control line EM[n]. Referring to FIG.7, the reset line 436 is parallel to the initialization voltage wiringVint.

In addition, each of the output line 437 and the sensor power line 438may be parallel to one of the data line DATA[m] and the first power lineELVDD. Referring to FIG. 7, the output line 437 and the sensor powerline 438 are parallel to the data line DATA[m].

Referring to FIG. 7, the sensing TFT 30 is disposed among the OLEDs on aplane, which may minimize interference with emission of light generatedin the OLED.

Hereinafter, an operation of the pixel illustrated in FIG. 7 will bedescribed in detail with reference to FIG. 8.

First, while the TFT T4 is in an on state according to a scan signaltransmitted through the additional scan line SCAN[n−1], aninitialization voltage is applied to one end of the first capacitor Caand the gate electrode of the driving TFT T1.

Next, the switching TFT T2 and the compensation TFT T3 are turned onaccording to a scan signal transmitted through the scan line SCAN[n].While the switching TFT T2 and the compensation TFT T3 are in an onstate, a data voltage transmitted through the data line DATA [m] istransmitted to the source electrode of the driving TFT T1, and thedriving TFT T1 is in diode-connection.

In such an example embodiment, a voltage subtracted from the datavoltage by a threshold voltage of the driving TFT T1 is applied to thegate electrode and the source electrode of the driving TFT T1.

Next, the TFTs T5 and T6 are turned on according to a light emissioncontrol signal transmitted through the light emission control lineEM[n], and by an increase of the scan signal transmitted through thescan line SCAN[n], a voltage of the gate electrode of the driving TFT T1is boosted.

While the two TFTs T5 and T6 are in an on state, a voltage of the firstpower line ELVDD is applied to the source electrode of the driving TFTT1, and a driving current based on a gate-source voltage differenceflows through the driving TFT T1. The driving current is transmitted tothe anode of the OLED through the TFT T6 in an on state.

FIG. 9 is a cross-sectional view illustrating an OLED display device 103according to a third example embodiment.

The OLED display device 103 according to the third example embodimentincludes a light blocking layer 425 between a thin film encapsulationlayer 350 and a sensor SP. Referring to FIG. 9, the light blocking layer425 is disposed on the thin film encapsulation layer 350, a passivationlayer 455 is disposed on the light blocking layer 425, and a sensing TFT30 is disposed on the passivation layer 455 to overlap the lightblocking layer 425.

For example, the light blocking layer 425 is disposed between the thinfilm encapsulation layer 350 and a sensing gate electrode 431 of thesensing TFT 30. The light blocking layer 425 helps to prevent lightgenerated in an OLED 310 from directly affecting an oxide semiconductorlayer 420 of the sensing TFT 30.

FIG. 10 is a cross-sectional view illustrating an OLED display device104 according to a fourth example embodiment.

The OLED display device 104 according to the fourth example embodimentincludes a color filter 550 on a sensor SP. Referring to FIG. 9, awindow 510 is disposed on the sensor SP, and the color filter 550 isdisposed on the window 510. The color filter 550 overlaps the sensor SPincluding a sensing TFT 30.

The color filter 550 allows only light of a predetermined color to reachan oxide semiconductor layer 420 of the sensing TFT 30. Accordingly, thesensor SP may sense an intensity of the predetermined color.

Referring to FIG. 10, lights L3 and L4 emitted from an OLED 310 passthrough the color filter 550 when they are incident to the oxidesemiconductor layer 420 after being reflected by a reflection object561, for example, a colored object, or a finger, stylus, etc. Forexample, when the color filter 550 is a red color filter, a red light L3passes through the color filter 550 to be incident to the oxidesemiconductor layer 420. On the other hand, a light L4 of a color otherthan the red color is absorbed by the color filter 550 and fails toreach the oxide semiconductor layer 420. Accordingly, the sensor SP maysense an intensity of the red light.

For example, in the case where a plurality of sensors SP independentlycapable of sensing blue, red, and green colors, respectively, aredisposed on a thin film encapsulation layer 350, a color of thereflection object 561 may be identified based on integrated analysis oncolor intensity information obtained from each sensor SP. In the casewhere these sensors SP are arranged at high density, an image of thereflection object 561 may be recognized by the sensor SP.

FIG. 11 is a plan view illustrating an OLED display device 105 accordingto a fifth example embodiment.

The OLED display device 105 according to the fifth example embodimenthas a display area DA and a fingerprint recognition sensor FPS at aportion of the display area DA.

The fingerprint recognition sensor FPS may be disposed at a portion of athin film encapsulation layer 350 and may include a plurality of sensorsSP. The sensor SP arranged for fingerprint recognition may be referredto as a fingerprint recognition sensor.

For fingerprint recognition, a main control 900 may include afingerprint recognition storage. In addition, the sensor SP may beconnected to the fingerprint recognition storage.

In addition, a fingerprint information of a predetermined user may bestored in the fingerprint recognition storage. Accordingly, whether ornot a fingerprint recognized using the fingerprint recognition sensorFPS matches the fingerprint of the predetermined user may be verified.In the case where the fingerprint recognized using the fingerprintrecognition sensor FPS matches the fingerprint of the predetermineduser, the OLED display device 105 may be unlocked, for example.

By way of summation and review, display devices may be made to receiveinput of information by contact with, for example, a finger or a styluspen and a screen. Such display devices having an information inputfunction may be used for, for example, a mobile phone, a personaldigital assistant (“PDA”), a portable game machine, a car navigationsystem, an automated teller machine (“ATM”), and the like. A displaydevice having an information input function may be manufactured by, forexample, separately manufacturing a touch panel and combining it with adisplay panel, or by forming various sensors directly in the displaypanel.

As described above, embodiments relate to an OLED display device havingan information display function and an information input function.

In one or more example embodiments, the OLED display device has a simplestructure while having both an information display function and aninformation input function.

Example embodiments have been disclosed herein, and although specificterms are employed, they are used and are to be interpreted in a genericand descriptive sense only and not for purpose of limitation. In someinstances, as would be apparent to one of ordinary skill in the art asof the filing of the present application, features, characteristics,and/or elements described in connection with a particular embodiment maybe used singly or in combination with features, characteristics, and/orelements described in connection with other embodiments unless otherwisespecifically indicated. Accordingly, it will be understood by those ofskill in the art that various changes in form and details may be madewithout departing from the spirit and scope as set forth in thefollowing claims.

What is claimed is:
 1. An organic light emitting diode display device,comprising: a substrate; a plurality of organic light emitting diodes onthe substrate; a thin film encapsulation layer on the organic lightemitting diodes; a window on the thin film encapsulation layer; and atleast one sensor between the plurality of organic light emitting diodesand the window, the at least one sensor including at least one sensingthin film transistor.
 2. The organic light emitting diode display deviceas claimed in claim 1, wherein the sensor is between adjacent organiclight emitting diodes.
 3. The organic light emitting diode displaydevice as claimed in claim 1, wherein each organic light emitting diodeof plurality of organic light emitting diodes includes: a firstelectrode; an organic light emitting layer on the first electrode; and asecond electrode on the organic light emitting layer.
 4. The organiclight emitting diode display device as claimed in claim 3, furthercomprising a pixel defining layer between the first electrodes, thesensor vertically overlapping the pixel defining layer.
 5. The organiclight emitting diode display device as claimed in claim 1, furthercomprising a light blocking layer between the thin film encapsulationlayer and the sensor.
 6. The organic light emitting diode display deviceas claimed in claim 1, further comprising a color filter on the sensor.7. The organic light emitting diode display device as claimed in claim1, wherein the sensing thin film transistor includes: a sensing gateelectrode; a semiconductor layer overlapping the sensing gate electrode;a sensing source electrode connected to the semiconductor layer; and asensing drain electrode spaced apart from the sensing source electrodeand connected to the semiconductor layer.
 8. The organic light emittingdiode display device as claimed in claim 7, wherein the semiconductorlayer includes an oxide semiconductor layer.
 9. The organic lightemitting diode display device as claimed in claim 1, wherein the sensoris between the thin film encapsulation layer and the window.
 10. Anorganic light emitting diode display device, comprising: a substrate; aplurality of organic light emitting diodes on the substrate; a thin filmencapsulation layer on the organic light emitting diodes; a window onthe thin film encapsulation layer; at least one sensor between theplurality of organic light emitting diodes and the window; and a lightblocking layer between the thin film encapsulation layer and the sensor.11. The organic light emitting diode display device as claimed in claim10, further comprising a color filter on the sensor.
 12. The organiclight emitting diode display device as claimed in claim 10, wherein thesensor includes at least one sensing thin film transistor.
 13. Theorganic light emitting diode display device as claimed in claim 12,wherein the sensing thin film transistor includes: a sensing gateelectrode; a semiconductor layer overlapping the sensing gate electrode;a sensing source electrode connected to the semiconductor layer; and asensing drain electrode spaced apart from the sensing source electrodeand connected to the semiconductor layer.
 14. The organic light emittingdiode display device as claimed in claim 13, wherein the semiconductorlayer includes an oxide semiconductor layer.
 15. The organic lightemitting diode display device as claimed in claim 10, wherein the sensoris between the thin film encapsulation layer and the window.
 16. Anorganic light emitting diode display device, comprising: a substrate; aplurality of organic light emitting diodes on the substrate; a thin filmencapsulation layer on the organic light emitting diodes; a window onthe thin film encapsulation layer; and at least one sensor between theplurality of organic light emitting diodes and the window, the at leastone sensor including a thin film transistor having an oxidesemiconductor layer.
 17. The organic light emitting diode display deviceas claimed in claim 16, further comprising a light blocking layerbetween the thin film encapsulation layer and the oxide semiconductorlayer.
 18. The organic light emitting diode display device as claimed inclaim 16, further comprising a color filter on the oxide semiconductorlayer that overlaps the oxide semiconductor layer but does not overlapany of the plurality of organic light emitting diodes.
 19. The organiclight emitting diode display device as claimed in claim 16, furthercomprising a color filter on the oxide semiconductor layer that allowsonly light of a predetermined color to reach the oxide semiconductorlayer, wherein the color filter and the oxide semiconductor layer arelocated between a first organic light emitting diode that emits light ofthe predetermined color and a second organic light emitting diode thatdoes not emit light of the predetermined color.
 20. The organic lightemitting diode display device as claimed in claim 16, furthercomprising: a sensing gate electrode, wherein the oxide semiconductorlayer overlaps the sensing gate electrode; a sensing source electrodeconnected to the oxide semiconductor layer; and a sensing drainelectrode spaced apart from the sensing source electrode and connectedto the oxide semiconductor layer.
 21. An organic light emitting diodedisplay device, comprising: a substrate; a plurality of organic lightemitting diodes on the substrate; a thin film encapsulation layer on theorganic light emitting diodes; a window on the thin film encapsulationlayer; at least one sensor between the plurality of organic lightemitting diodes and the window; and a color filter on the sensor thatoverlaps the sensor but does not overlap any of the plurality of organiclight emitting diodes.
 22. The organic light emitting diode displaydevice as claimed in claim 21, wherein the sensor includes at least onesensing thin film transistor.
 23. An organic light emitting diodedisplay device, comprising: a substrate; a plurality of organic lightemitting diodes on the substrate; a thin film encapsulation layer on theorganic light emitting diodes; a window on the thin film encapsulationlayer; at least one sensor between the plurality of organic lightemitting diodes and the window, the at least one sensor including a thinfilm transistor; and a color filter on the sensor that allows only lightof a predetermined color to reach an oxide semiconductor layer, whereinthe color filter and the sensor are located between a first organiclight emitting diode that emits light of the predetermined color and asecond organic light emitting diode that does not emit light of thepredetermined color.